Rock drill



0a. 25, 1932. E G RTW 1,884,651

ROCK DRILL Filed Feb. 2, 1929 may.

Patented Oct. 25, 1932 PATENT Fries ELMEB G'ARTIN, OF GLAB-EMONT, NEW HAMPSHIRE, ASSIGNOR 'IO SULLIVAN MACHINERY COMPANY, A CORPORATION 9F MASSACHUfSETTS R CK DRILL Application. filed February 2, 1929. Serial No. 337,061.

My invention relates to rock drills and particularly to devices for cleansing the hole dur ing drilling.

An object of my invention is to provide an improved rock drill having improved means for elieoting a hole blowing operation. Another object of my invention is to provide an improved hole blowing device whi h shall be of very simple and rugged construction. A further object of the invention is to provide an improved hole blowing device capable of bein easil and uickl' controlled the ooa Y .5 l

orator. A more specific object of the inventionis toprovide an improved hole blowing device of the type adapted to close a free haust port in the cylinder and simultaneously effect continuous supply of motive fluid to the front end of the cylinder. Other objects and advantages of the invention will appear during the course of the following specification and claims.

In the accompanying drawing I have shown for purposes of illustration one em bodiment which my invention may assume in practice.

In this drawing,

1 shows a longitudinal section through a rock drill with the ends broken away, parts being shown in elevation.

Fig. 2 is a fragmentary sectional view on line 2-2 of Fig. 1 through my improved hole cleansing means. 7

Fig. 8 i s a similar transverse section on line 33 of Fig. 1. V

Fig. l is a detail perspective view of the slide valve of my improved hole cleansing means.

Fig. 5 is a developed sectional view showing passa es controlled by the slide valve.

Referrin to the particular embodiment of my invention as herein shown, thedrill with which I have shown my improvement associated comprises a cylinder 5 havin a piston 6 reciprocable therein, which piston has integral forwardly eaten ding striklngbar 2'' adapted to hammer on the shank 8 of rock drill steel. This drill. steel has a longitudinal passage 9 extending to its ou ,g e d and this passage may be supplied with ch11 H'QSSQCl air, a'cle'ansing liquid, or a mixture of both,

for the purposes of cleansing the cuttings and removing them from the hole. In this embodiment there is illustrated a central water tube 10 having its iorward'end received loosely in bore 9 of the drill steel, as is common in the art. During normal operation, when the piston is in the rearward part of its travel, some pressure fluid passes down through the grooves 11 on the striking bar 7 into the chamber surrounding the shank of the drill steel and thus pass into the bore 9 where it mixes wi the watesi'lowin through tube 10,if such tube be provided, and assists in cleansing the hole. This is accomplished by reason of the fact thatthe grooves 11 withdraw into the cylinder from the buffer ring 12 which is interposed between the cylinder and the chuck housing or front cylinder head member 13. In drilling deep holes and particularlyin certain kinds of formation, this supply of pressure fluid is not sufiicient to cleanse the cuttings from the hole and my invention pertains to an improved device for intermittentl sto in the operation of the hammer niston and introducing a much larger quantity of pressure fluid to the bore 9 forblowing the cuttings from the hole.

Any suitable fluiddistribution means for eiiecting admission and exhaust of motive.

has laroe diameter aortion 17 which is received in an enlarged bore 17 of the valve chest, a reduced portion 18 providing a constant pressure area 19, and a still further recluced end portion 20. An outside annular groove 22 is formed in the valve for purposes which will presently appear. The rearward area on the large diameter portion 17 communicates with the cylinder by means of athrow passage 21 shown in dotted lines. A passage 23 connects an annular groove 24; in the valve chest with the front end of the cylthe rear end of the cylinder.

inder. The fluid distribution means also includes a free cylinder exhaust port 25 controlled by the piston. Passage 23 serves to admit pressure fluid from the valve chest to the forward end of the cylinder when the valve is thrown to its forward position.

In operation, pressure fluid passes through the inlet 15 to the rear end of the cylinder when the valve is in the position shown and drives the piston forwardly to strike a blow on the drill steel. The valve is held in this position by live pressure acting on theforwardly facing areas of the valve. During the forward stroke the throw passage 21 is uncovered, admitting live pressure fluid to the rear surface on thelarge diameter portion 17 to throw the valve forwardly. This area is of suiiicient extent to overcome the pres- .sure acting on the forwardly facing areas of the valve which are exposed to pressure in The piston uncoversthe cylinder exhaust port 25 and the .rear end of the cylinder is exhausted. When thevalve is thrown, its front end cuts off admission to the rear of the cylinder and admission takes place to the front end of ti e cylinder from inlet groove 16 around annular groove 22 on the valve, groove 24 in the valve chest and passage 23. The piston is then driven rearwardly and. after, cylinder exhaust-port 25 is covered, compression takes place in the rear end of the cylinder and this compression pressure acts on the forwardly facing surfaces of the valve to throw the same 'rearwardly to the position shown, and the same cycle of events is repeated over and over. It will be. understood that the rear surface of the enlarged portion 17 of the valve will havebeen relieved of pressure since passage 21 has been in communication with the exhaust and the only substantial pressure which needs to be overcome in throwing the valve rearwardly is the constant pressure acting on shoulder 19; When the piston is in the rear end of its stroke, the grooves 11 will serve to Y establish communication between the front end of the cylinder and the chamber surrounding the shank 8 of the drill steel.

My improved hole blowing device will next be described. An integral boss 26 projects laterally from the cylinder adjacent the cylinder exhaust port and'in this bossareformed a pan of longitudlnal guiding grooves 27 which are connected in front of thecylinder conical recess 35 whereby the valve is normally retained in inoperative position. A. passage 36 extends longitudinally through the cylinder wall and communicates directly with the free cylinder exhaust port at one end and with the enlarged bore 17 of the valve chest at its other end in about the same trans- "verse plane as the throwing passage 21.

When it is desired to effect a hole blowing operation, the operator moves the handle 30, whereupon the slide valve covers the exhaust port 25 and prevents exhaust of motive fluid from the front end of the cylinder. A pressure will be very quickly built up at this point which is simultaneously transmitted through the passage .36 tothe large throwing surface on portion'l'? of the valve whereby the valve is held continuously in its forward position. Motive fluid then passes continuously through passage 23 to the front end of the cylinder and, since it is not permitted to escape through port 25, a large quantity will pass through grooves 11 in the striking bar and build up a substantial pressure in the chamber surrounding the shank of the drill steel. This supplies fluid at live pressure to the bore in the drill steel, which is very effective in blowing the cuttings from the drilled hole. The slide valve 28 is maintained in its closed position by the pressure of the fluid in the cylinder. As soon as the hole is cleaned, the operator again opens the exhaust controlling valve and normal operation of the machine is automatically resumed.

As a result of my invention it will be apparent that an improved device of very simple and rugged construction has been provided for effecting a hole blowing operation, andthat at the same time means are provided under the control of a slide valve for causing the distribution valve to be held in such positionas to supply motive fluid to the front end of the cylinder continuously. The slide valve of my invention has very decided advantages over an oscillating valve from the standpoint of ease of operation and simplicity of construction.

While I have'in this application specifically described one embodiment which the invention may assume in practice, it will be understood thatthis form of the same is shown for purposes of illustration and that the invention maybe modified and embodied in various other forms without departing from its spirit or the scope of the appended claims.

What I claim as new and desire to secure by Letters Patent is :v

1. In a rock drill, the combination of a cylinder having ports and passages for the admission and-exhaust of motive fluid, a piston reciprocable therein, said cylinder having insition to close the exhaust port, said slide valve being maintained in its closed position by the pressure of the fluid in the cylinder, and a drill bit having a longitudinal passage for the motive fluid from the end of the cylinder to its cutting end.

2. In a reel: drill, the combination of a cylinder, apiston reciprocable therein, fluid distribution means therefor including an exhaust port in the cylinder wall intermediate its length and governed by the piston, a drill steel having a longitudinal passage for metive fluid, means for establishing communication between said passage and the front end of the cylinder when the piston is in the rear endof the cylinder, said cylinder exhaust port being normally open when said piston is in the rear end of the cylinder, and a slide valve arranged exteriorly and longitudinally of the cylinder adapted to be moved into position to close said exhaust port for effecting a hole blowing operation, said slide valve being maintained in its closed position by the pressure of the fluid in the cylinder.

3. In a rock drill, the combination of a cylinder, a piston reciprocable in said cylinder, fluid distribution means for controlling admission and exhaust of motive fluid in eluding an exhaust port in said cylinder intermediate its length and governed by the piston and a distributing value adapted in one position to effect admission of motive fluid to the front end of the cylinder, a drill steel arranged to be pereussively actuated by said piston and having a longitudinal passage for motive fluid to its cutting end, means for establishing communication between said passage and the front end of said cylinder when the piston is in the rear end of the cylinder, and means for simultaneously closing said exhaust port and efl'ecting supply of pressure fluid to an area on said valve to hold the latter in position to admit motive fluid continuously to the front end of the cylinder to effect a hole blowing operation.

41. In a rock drill, the combination set forth in claim 3 wherein said last mentioned means comprises a valve for closing said exhaust port and a passage, the pressure in which is controlled by said valve, for admitting pressure fluid to said area on the distribution valve.

5. In a rock drill, the combination set forth in claim 3 wherein said last mentioned means comprises a valve arranged exteriorly of the cylinder for closin said exhaust port and a u h I passage leadlng from said exhaust port to said area on the distribution valve and ar-.

ranged to be supplied with pressure fluid from the front end of the cylinder when the exhaust port is closed.

6. In a rock drill, the combination set forth in claim 3 wherein said last mentioned means comprises a slide valve arranged exteriorly of the cylinder and adapted to close said exhaust port, and a passage leading from said distributionmeans for eflecting admission and exhaust of motive fluid, a drill steel arranged to be pereussively actuated by said piston having a longitucunal passage for pressure fluid to its cutting end, means for placin said passage in communication with the ward portion of its stroke, said cylinder havng intermediate its length and governed by the piston an eyhaust port, and means for closing said eznaust port to effect a hole blowing operation comprising a valve arranged eyeriorly of and slidable longidinally of the cylinder to efleet closing of aid exhaust port at will, said slide valve bemaintained in its closed position by the pressure of the fluid in the cylinder.

8. In a rock drill, the combination of a cylinder, a piston reciprocable therein, fluid distribution means for effecting admission and exhaust of motive fluid including a cylinder exhaust port governed by the piston, drill steel arranged to be percussively actuated by said piston having a longitudinal passage for pressure fluid to its cutting end, means for placing said passage in con munication with the cylinder when the piston is in the rearward portion of its travel, and means for closing said exhaust port to effect a hole blowing operation comprising a slide valve and longitudinally extending guideways formed on said cylinder exteriorly thereof for slidably receiving said valve, said slide valve maintained in its closed position outwardly against its guideways by the pressure of the fluid in t is cylinder.

9. In a rock drill, the combination of a cylinder, a piston reciprocable therein, means for distributing live fluid pressure to each end of said cylinder including a distributing valve, a free exhaust port controlled by said piston, a drill steel arranged to be percussively actuated by said piston and having a lcngitud aal passage for conducting cleansing fluid to its cutting end, means for establishing communication between said drill steel pa the front end of said cylinder when the piston is in the rear end thereof, and manually operable valve mechanism for closin said exhaust port and for directa su ply of pressure fluid to an area on said distributin valve to hold the latter in position to admit motive fluid to the front end of said cylinder to effect hole blowing operation.

10. In a reel: drilhthe comlination of a cylinder, piston reciprocable therein, a throttle valvefor controllin the fluid supply, means for d' ribu live pressure fluid from said supply to eacn end of said cylinder including a distributin valve, a free exhaust .75 cylinder when the piston is m the rearport controlled by said piston, a drill steel arranged to be percussively actuated by said piston and having a longitudinal passage for conducting cleansing fluid to its cutting end, means for establishing communication between said drill steel passage and the front end of said cylinder when the piston is in the rear end of said cylinder, and a manually operable valve mechanism arranged along the side of said motor cylinder for closing said free exhaust port and for directing a supply of pressure fluid to an area on said distributing valve to hold the latter in position to admit pressure fluid to the front end of said cylinder to eflect a hole blowing operation.

In testimony whereof I affix my signature.

, ELMER G. GARTIN. 

